A number of systems have been used in the past to detect and/or monitor the effects of an impact from an object, for example a projectile on a body. In a laboratory environment plastina clay has typically been used when trialling or testing the ballistic type effects of an impact from a projectile, such as a bullet for example, on a body whereby the plastina clay simulates body composition. Using this type of system it is not possible to measure the actual back face velocity of an armour plate for example that is placed in front of the plastina clay. Therefore, measurements relating to the impact of the projectile on the body are inferred by indirect methods as a result of an analysis undertaken on deformation of the plastina clay.
Detecting the penetration of impacts on a body may also be measured by using a mesh fabric incorporating fibre optics placed on armour worn by a user. When a fibre is broken, it is assumed to be caused by a penetrating impact. However, this type of system is generally very fragile and cannot be used to accurately determine a ballistic impact from a rip or tear in the armour fabric caused by other sources.
Other ballistic impact detection systems incorporate peizo electric film sensor elements attached to body armour for example. The peizo film sensors detect acoustic vibration patterns caused by impacts and convert them into a voltage. The voltage is passed through a circuit which determines if the impact has the frequency and amplitude characteristics that have become associated with typical impacts that cause injuries. The voltage output from the peizo film sensors feed a battery powered analogue or digit circuit which has to be carried by the user or combatant. The circuitry is used to isolate the high energy acoustic signatures produced by ballistic impacts and discerns the approximate impact location on the body. This type of system requires a considerable amount of signal processing and filtering of the acoustic signatures in order to discriminate impact signature information from noise for example in order to provide useable impact data output.
There is therefore a need for an impact detection system for detecting and monitoring the effects of impacts on a body and in particular but not exclusively, impacts that might cause injury.
In this specification if reference has been made to patent specifications, other external documents, or other sources of information, this is generally for the purpose of providing a context for discussing the features of the invention. Unless it is specifically stated otherwise, reference to such external documents is not to be construed as an admission that such documents, or such sources of information, in any jurisdiction, are prior art or form part of the common general knowledge in the art.
It is an object of the present invention to provide improved impact detection system for detecting and measuring impact related characteristics on a body, or at least to provide industry or the public with a useful choice.